Photodynamic therapy system, device and associated method of treatment

ABSTRACT

As one example, a photodynamic therapy system can include a flexible panel comprising a plurality of light sources distributed across a conformable light delivery surface thereof. The plurality of light sources can be configured to provide a treatment light to achieve a desired therapeutic effect at a predetermined distance from the light delivery surface. The system can also include a spacer configured at the light delivery surface to position the light delivery surface at the predetermined distance from a treatment area of a patient.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Patent Application No. 61/383,365, filed on Sep. 16, 2010, and entitled FLEXIBLE PHOTODYNAMIC THERAPY DEVICE AND METHOD FOR LARGE HETEROGENEOUS LESIONS and U.S. Provisional Patent Application No. 61/383,390, filed on Sep. 16, 2010, and entitled PHOTODYNAMIC THERAPY INCLUDING LIGHT PRETREATMENT. The entire contents of each of the above-identified patent applications are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to a photodynamic therapy system, device and associated method of treatment.

BACKGROUND

Photodynamic therapy (PDT) involves the activation of a pharmaceutical (called a photosensitizer) by a given wavelength of light to cause the targeted destruction of cells, such as through apoptosis. Photosensitizers can be administered topically or systemically. Various techniques have been developed to monitor the absorption of photosensitizers into tissue and the progress of photodynamic therapy, including without limitation fluorescence and reflectance spectroscopy and singlet oxygen monitoring. For example, spectroscopy before, during, and after photodynamic therapy may provide useful dose metrics and enable therapy to be tailored to individual lesions. Light sources and monitoring devices have been developed which work for relatively small lesions. However, these devices may not be suited for the large, heterogeneous lesions that frequently occur with diseases such as psoriasis and eczema. Additionally, existing devices tend to be unduly costly and complicated to implement.

SUMMARY

This disclosure relates to a photodynamic therapy system, device and associated method of treatment.

As one example, a photodynamic therapy system can include a flexible panel comprising a plurality of light sources distributed across a conformable light delivery surface thereof. The plurality of light sources can be configured to provide a treatment light to achieve a desired therapeutic effect at a predetermined distance from the light delivery surface. The system can also include a spacer configured at the light delivery surface to position the light delivery surface at the predetermined distance from a treatment area of a patient.

As another example, a photodynamic therapy device can include a plurality of generally rigid tiles. Each of the plurality of tiles can include a plurality of light sources distributed across a respective surface thereof. Each of the plurality of tiles can be flexibly connected in a distributed arrangement to provide a conformable light delivery surface. The plurality of light sources can be configured to receive electrical power and provide a treatment light to achieve a desired therapeutic effect at treatment area located a predetermined distance from the light delivery surface.

As yet another example, a method for photodynamic therapy (PDT), can include applying a photosensitizer to a treatment area of a patient's skin and attaching a PDT device to cover at least a substantial portion of the treatment area. The PDT device can include a plurality of light sources distributed across a conformable light delivery surface such that, following the attachment, a spacer at the light delivery surface separates the light delivery surface from the treatment area by approximately a predetermined distance. The method may also include controlling a plurality of light sources to provide a treatment light to activate the photosensitizer applied at the treatment area.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an example of a photodynamic therapy (PDT) system.

FIG. 2 depicts an example of a PDT device according to an embodiment.

FIG. 3 depicts an example of a PDT device according to another embodiment.

FIG. 4 depicts an example of a PDT device according to yet another embodiment.

FIG. 5 depicts a perspective view of the PDT device of FIG. 4.

FIG. 6 depicts an example of a PDT device according to another embodiment.

FIG. 7 is a partial view of a PDT device demonstrating an example of a connection between light tiles according to an embodiment.

FIG. 8 is a partial view of a PDT device demonstrating an example of a connection between light tiles according to another embodiment.

FIG. 9 is an exploded view of a part of a PDT device demonstrating an example assembly of a light tile according to an embodiment.

FIG. 10 is a partial view of a PDT device demonstrating example features residing at a back surface thereof according to an embodiment.

FIG. 11 is an exploded view demonstrating an example of a PDT device and spacer according to an embodiment.

FIG. 12 is an exploded view demonstrating an example of a PDT device and spacer according to another embodiment.

FIG. 13 demonstrates an example of a PDT device and spacer in a curved orientation according to an embodiment.

FIG. 14 demonstrates an example of the PDT device and spacer of FIG. 13 attached about a portion of a patient's arm according to an embodiment.

FIG. 15 demonstrates an example of a photodynamic therapy system that can be implemented according to an embodiment.

FIG. 16 is a flow diagram depicting an example treatment method that can be implemented according to an embodiment.

FIG. 17 is a flow diagram depicting an example method of controlling a photodynamic therapy system that can be implemented according to an embodiment.

DETAILED DESCRIPTION

This disclosure relates to a photodynamic therapy (PDT) device, system and method for providing photodynamic therapy. In one example, the PDT system can include a flexible panel that includes a plurality of light sources distributed across a conformable light delivery surface thereof. The light delivery surface corresponds to the side from which the treatment light emanates. The light sources may be exposed or an optically transparent cover may be placed over the light sources. The light sources can be configured to provide a treatment light to achieve a desired therapeutic effect at a predetermined distance from the light delivery surface. During treatment, a spacer can be interposed between the light delivery surface of the flexible panel and the treatment area such as to prevent contact between the light delivery surface and the treatment area. The spacer, which may be disposable, can be configured to position the light delivery surface at the predetermined distance from a treatment area of patient's skin or the spacing can be provided by structural features on the PDT device itself. The term disposable means that after use the spacer can be discarded, although it does not require that a given spacer be used only a single time. For instance, a given spacer, if sufficiently durable, can be cleaned and re-used.

In one example, a PDT panel can include a plurality of tiles that each includes a plurality of light sources (e.g., light emitting diodes (LEDs)) distributed across the surface thereof. Each of the tiles can be flexibly connected as to provide the conformable light delivery surface of the PDT panel. A control system can also control parameters (e.g., wavelength, fluence, duration and/or fluence rate) associated with the delivery of the treatment light. The control system can also selectively control parameters for operating one or more groups of the light sources independently, as disclosed herein.

The light sources can be configured on a given PDT panel to provide light with a wavelength designed to activate a predetermined photosensitizer. As an example, the photosensitizer can be implemented as a phthalocyanine photosensitizer, such as a class of phthalocyanine photosensitizers that includes a diamagnetic metal or metalloid. As one example, the photosensitizer can be a phthalocyanine photosensitizer that includes a diamagnetic metal and a ligand attached to the metal, such as the photosensitizer Pc 4.

After the photosensitizer has been applied to the treatment area, the light sources can be controlled to deliver light for a duration and with a fluence sufficient to activate the photosensitizer and achieve a desired therapeutic effect. As used herein, the term fluence can refer to the light energy delivered per unit area (e.g., J/cm²). Hence the fluence rate refers to the rate at which the light energy is delivered to the treatment area.

As used herein, the term “lesion” can refer to skin disorders, diseases and wounds. A lesion may be located on the outer surface of the skin, beneath the outer surface of the skin, and combinations thereof. The device, systems and methods disclosed herein can be utilized for photodynamic therapy to treat large heterogeneous lesions, such as for diseases like psoriasis or eczema that may be present at one or more locations on a patient's body. Other examples of lesions that may be treated based on this disclosure can include actinic keratosis, cutaneous T-cell lymphoma, other skin cancers, fungal infections, microbial infections, viral infections, vitiligo, diabetic and non-diabetic ulcers and combinations thereof. The systems and methods disclosed herein can also be utilized to treat other skin disorders, lesions, diseases and wounds, such as may be located on the outer surface of the skin, beneath the outer surface of the skin and combinations thereof. Moreover, the systems and methods disclosed herein are also applicable to provide treatment for cosmetic purposes, such as for photo rejuvenation and other cosmetic applications.

FIG. 1 demonstrates an example of a photodynamic therapy (PDT) system 10 that can be implemented according to an embodiment. The system 10 can include one or more PDT devices 12, demonstrated in the example of FIG. 1 as PDT device 1 through PDT device N, where N is a positive integer greater than or equal to 1 (N≧1). Each PDT device 12 can be in the form of a flexible panel that includes a plurality of light sources 14 distributed across a conformable light delivery surface thereof. As used herein, the term “conformable” and variants thereof mean that the panel is sufficiently pliant to take on the general shape of an object or structure to which it is applied and can remain in such a configuration. For example, if the panel of a PDT device is applied to a cylindrical object (e.g., a portion of a limb), the light delivery surface adapts to the contour of the cylindrical object such that it also has a generally cylindrical configuration corresponding to the object.

The light sources 14 can be distributed and arranged along the light delivery surface such that the desired effect by the treatment light is discernable at a predetermined distance from the light delivery surface. Each of the light sources 14 can be configured to provide a treatment light which, at the predetermined distance, is operative to achieve a desired therapeutic effect. For example, the light sources 14 can be implemented as semiconductor light sources, such as light emitting diodes (LEDs), including organic LEDs, quantum dot LEDs or other types of light sources that may provide treatment light with a fluence and wavelength sufficient to achieve the desired therapeutic effect. In one example, the therapeutic effect can be activation of a photosensitzer to produce reactive oxygen species (e.g., singlet oxygen) in diseased tissue at the treatment area of the patient. For the example of a phthalocyanine photosensitizer (e.g., Pc 4), each of the plurality of light sources 14 can be configured to provide the treatment light with a red wavelength in range from about 665 nm to about 680 nm. The particular wavelength of the treatment light can be set depending on the particular photosensitizer that is applied to the treatment area and the desired level of photosensitizer activation, such as ranging from about 620 nm to about 800 nm.

Examples of semiconductor materials that can be utilized for LED light sources for the red wavelength include Aluminium gallium arsenide (AlGaAs), Gallium arsenide phosphide (GaAsP), Aluminium gallium indium phosphide (AlGaInP), and Gallium (III) phosphide (GaP). Because of the high power typically utilized to energize the LEDs for treatment, the LEDs can be mounted on or thermally coupled to a heat sink to facilitate heat dissipation. Other means to help dissipate heat can also be utilized (e.g., fans, cooling fluids, heat pipes or the like) in addition to or as an alternative to heat sinks.

Each PDT device 12 can also include corresponding circuitry 16 to operate the light sources 14 for delivering the treatment light. The circuitry 16 can include electrical conductors for supplying the electrical energy to the light sources 14. The circuitry 16 may also include switching circuits to selectively activate and deactivate light sources, such as by controlling the flow of current from reaching the light sources. As a further example, the circuitry 16 can implement power electronics to control the delivery of power to the light sources, such as in response to external control signals.

The circuitry 16 can also be configured to provide feedback corresponding to operation of the PDT device 12 and/or one or more sensed condition (e.g., for the PDT device, a patient condition, environmental condition). The sensed condition information can be provided as feedback to an associated control system 24 or it can be stored in local memory (e.g., also part of the circuitry). For example, the circuitry 16 can include a temperature sensor configured and arranged to sense a temperature, which can include the temperature of a treatment area on the patient's body 20, the temperature of one or more places on the PDT device, and/or the environmental temperature. As another example, the circuitry can include a spectrometer or other device configured to monitor the absorption of photosensitizer into tissue and provide an indication of the progress of photodynamic therapy, such as via fluorescence spectroscopy, reflectance spectroscopy or singlet oxygen monitoring, for example. The circuitry 16 can also include other types of sensing circuits (e.g., moisture sensors, accelerometers), which can vary according to application requirements and cost constraints.

A spacer 18 can help position the light delivery surface at a predetermined distance from a treatment area of a patient's body 20 to which the PDT device 12 has been applied. The spacer 18 can be removably attached at the light delivery surface, it can be a structural portion of the PDT device 12 or it can be implemented by including a removable portion and another portion that is part of the PDT device. Any number of one or more such spacers 18 can be utilized with each PDT device depending upon its construction. The spacer 18 thus can operate as an attachment device configured to optically couple the device at the treatment area of the patient's body 20. The spacer can be substantially optically transparent as to permit transmission of light at or about the wavelength of the treatment light through the spacer 18. As used herein, the term substantially means that the desired property or effect (e.g., being optically transparent) is intended, although it may not be completely transparent as a small percentage (e.g., about 10% or less) of treatment light may be blocked; however, it is transparent enough for delivery of a sufficient amount of the treatment light to the treatment area to achieve a desirable therapeutic effect.

In one example, the spacer 18 can include a sheet of flexible material that includes a substantially planar portion from which one or more protruding elements extends outwardly. The protruding elements can extend outwardly by a distance that is about or approximately the predetermined distance from the light delivery surface to which the treatment light is to be provided. The protruding elements can be configured sufficiently small (e.g., as tabs or stops) and distributed across the surface as to minimize interference with the delivery of the treatment light. For example, the protruding elements can be tapered or pointed as to substantially minimize contact with the treatment area.

The protruding elements may be configured with some structural rigidity to maintain the distance between the light delivery surface and the treatment area. Alternatively, corresponding protruding elements can be implemented on the light delivery surface to provide structural support and over which the corresponding flexible (e.g., providing minimal structural support or flaccid) protruding elements of the spacer can be utilized. In an alternative example, the spacer 18 may include no protruding elements, but instead be a flexible sheet of material that can conform to the configuration of the light delivery surface while protruding elements from the light delivery surface can provide the structural support to maintain the surface apart from the treatment area.

Since each of the PDT devices and associated light delivery surfaces thereof may be provided in different shapes and sizes, the spacer 18 can be specifically molded according to the dimensions and configurations of the light delivery surface of each respective PDT device 12. Alternatively, a common configuration of spacer may be designed for use with each different configuration of PDT device 12.

As one example, the spacer can be formed as a molded sheet of a flexible thin film material having an average thickness that is less than one millimeter. Examples of thin film materials can include low density polyethylene (LDPE), polyvinyl chloride (PVC), linear low density polyethylene (LLDPE), as well as other polyethylene or polypropylene materials. As a further example, the spacer can be formed of a thin flat sheet of a film (e.g., less than about 10 mil thick, such as about 5 mils or less), such as can be provided from a roll of spacer material (e.g., similar to a thin plastic wrap or cling film used for food storage). The sheet of material thus can be used to cover the treatment area to prevent contact with the surface during treatment.

Each PDT device 12 can also include a connector port 22 that provides for communication of information and power signals. For example, each connector port 22 can be connected to the control system 24 via a corresponding connection 26. The connections 26 can couple the connector ports 22 of the PDT devices with corresponding connector ports 28 of the control system 24. The ports can include receptacles configured to receive mating parts (e.g., connectors) therein. Alternatively, the connection 26 could be fixed to one or both of the ports 22 and 28.

The connections 26 can include electrical conductors such as for carrying power and information. Each connection 26 can include any number of conductors that is sufficient to provide a supply of electrical power and, if implemented, information signals. The power and control information can be carried on separate buses provided by the connections 26, such as corresponding to a power bus and a control bus. Additionally or alternatively, the control information can be sent over one or more shielded electrical conductors, via an optical communications link (e.g., an optical fiber) or wireless link that does not include the power signals. As another alternative example, control information may be encoded and transmitted through the connection 26 over one or more power buses.

The control system 24 can be configured to control the light sources 14 in each of the PDT devices 12, such as by providing power and/or control information to the PDT devices 12 via respective power and control buses. The control system 24 thus can include a power bus interface 27 configured to deliver power via the power buses to circuitry 16 of the PDT devices 12. The control system 24 can also include a control bus interface 29 to communicate control information with circuitry 16 of the PDT devices 12, which can be unidirectional or bi-directional communication. The control information can include instructions to the circuitry 16 for controlling the respective light sources. Additionally, the information sent via the control bus can include instructions to control other functions performed by circuitry 16 as well as for communicating feedback from the circuitry 16. As disclosed herein, the feedback can correspond to a condition of the device 12, the light sources 14 and/or a condition of the patient's body 20 that can be sensed via such circuitry (e.g., temperature, moisture or the like).

In the example of FIG. 1, the control system 24 can include memory 30 that can store computer readable instructions and data associated with the operation of the PDT system 10. The processor 32 can access the memory and execute instructions therein for implementing the control functions for the system. The memory 30 can be implemented as including one or more memory devices (e.g., RAM, ROM, solid state memory). While the control system is demonstrated as including a processor and memory, other types of hardware (e.g., a microcontroller, FPGA or the like) may be used to implement some or all the control functions.

The memory 30 includes computer readable instructions corresponding to a user interface 34 that can provide a human-machine interface for the system 10. The user interface 34, for example, can provide a means for entering or setting parameters for operation, which parameters can be stored in the memory, as demonstrated at 36. The parameters 36 can include a set of default parameters for operation of a given PDT device 12. Additionally, or alternatively, a user can employ the user interface 34 to modify the parameters 36 for a given patient and/or type of treatment.

The memory 30 can also include controls 38 programmed to implement a control routine for controlling operation of each PDT device 12 connected thereto. The controls 38 can be implemented to control the PDT devices 12 independently of one another, which can include concurrent operation or individual operation at separate times (e.g., sequentially in a rotating pattern). The controls 38 can employ the parameters 36 to control the delivery of treatment light by the light sources 14 to the treatment area, such as by controlling the duration, fluence and/or fluence rate of the treatment light. As an example, the controls 38 can be implemented to control the PDT device to supply the treatment light at the treatment area with a power ranging from about 20 J/cm² to about 200 J/cm² for a predetermined treatment duration. As another example, for certain applications, the controls 38 can be implemented to control the PDT device to supply the treatment light at the treatment area with a power ranging from about 80 J/cm² to about 120 J/cm² for a predetermined treatment duration. The treatment duration can also be programmable via the user interface 34, such as may be less than one hour (e.g., ranging from about 15 minutes to about 30 minutes), which further can vary depending on the fluence rate. As one example, the fluence rate can be greater than or equal to about 10 mW/cm². As another example, the fluence rate can be controlled to be within a range, such as ranging from about 10 mW/cm² to about 200 mW/cm² (e.g., ranging from about 80 mW/cm² to about 120 mW/cm²).

The duration, fluence and fluence rate can thus be programmed differently depending on, for example, the particular treatment protocol, the disease or other condition being treated. These and other parameters further may be adapted during treatment depending on the photosensitizer being used, the available power from the PDT device as well as patient sensitivity at the treatment area, for example.

As another example, in response to connecting a given PDT device 12 to the control system 24 (e.g., via a corresponding connection 26), information about the given device can be acquired (via the control bus). For example, each PDT device 12 can include a register or other type of memory structure that stores identifying data. The controls 38 can use such identifying data to determine the type and configuration of the particular PDT device. The controls 38 can further employ the acquired information to automatically set parameters 36 for controlling operation of the PDT device 12. The acquired information can also include an address for one or more addressable units (e.g., the PDT device itself, groups of light sources, sensors or the like), and the control system 24 can utilize such addresses for selectively communicating specific instructions to corresponding addressable units and/or for identifying the source of information and feedback provided via the control bus.

The controls 38 further can be programmed to selectively adjust the delivery of treatment light from the light sources 14 based on feedback. The feedback can be provided, for example, by the circuitry 16 through the control bus, such as corresponding to a sensed condition associated with the operation of the PDT device 12, or sensed condition of the patient's body 20. Additionally or alternatively, the feedback can correspond to a user input that is received via the user interface 34. For example, the patient or other user (e.g., a physician or technician) can employ an input device to provide feedback associated with the treatment, demonstrated an input/output (I/O) device 40. The input device 40, for example, can include a keyboard, a switch, a button, a touch screen associated with a control screen, a rheostat or other similar input device or a combination of input devices that can be utilized to input feedback or other information associated with programming the parameters 36 or entering other information about the treatment process or the patient. An I/O interface 42 can convert the signal provided via the input device(s) 40 into information useable by the control system 24, including the user interface 34.

As one example, a user or patient may use the input device 40 during treatment, such as in the event in response to experiencing a tingling sensation or discomfort or the absence of any physical sensation. In response to the user input, the controls 38 can adjust the parameters 36, such as to increase or reduce the power or fluence or fluence rate of the treatment light. Alternatively, a patient can vocalize the feedback to another user in response to which the user can employ the input device 40 to indicate the patient feedback to the control system 24.

By way of further example, the controls 38 can vary the power delivery during operation such as by ramping up the power (e.g., incrementally in steps or continuously) during the first part of the treatment and in response to feedback by a user (e.g., the patient or other user), the controls can terminate the ramp up, reduce to a maintenance level of power for the remainder of a treatment phase. Feedback such as power levels and other information (e.g., feedback) obtained before, during and after treatment can be stored in the memory 30, such as part of treatment data 54 for the respective patient.

As disclosed herein, the light sources may be arranged in individually controllable groups, such as implemented at one or more PDT device panels. The controls 38 can be programmed to selectively activate or deactivate each of such groups independently of each other. For example, the light groups can be arranged in individual tiles that are connected together to provide the light delivery surface of each PDT device 12. Each of the groups of light sources can be addressable via the control bus such that each group can be independently addressable and controlled by encoding header information in a control signal that is sent by the control system to one or more PDT device. For example, a user can employ the user interface 34, which can include a graphical representation of each of the light groups on a given PDT device, to selectively activate or deactivate one or more groups of light sources. The control signals can be routed to different output ports through the connectors depending upon the address.

As yet a further example, the controls 38 can be programmed to implement multiple phases of treatment such as can correspond to one or more pretreatment phases and a treatment phase. The pretreatment phase can be utilized to disrupt the stratum corneum such as to enhance penetration or increase the rate penetration of the photosensitizer into the treatment area during the treatment phase. The pretreatment and treatment phases may be implemented using the light sources 14.

By way of example, during the pretreatment phase, the controls 38 can employ operating parameters 36 programmed to control energization of the light sources 14 to deliver treatment light sufficient to provide for enhanced penetration of an activatable photosensitizer (e.g., Pc 4) into at least a portion of the treatment area of the patient's skin. The pretreatment phase can be implemented for a predetermined duration that is less than a subsequent treatment phase. For example, the pretreatment phase can deliver treatment light for a duration of about 5 to about 10 minutes or less versus about 15-30 minutes for treatment phase. In other examples, the pretreatment and treatment durations may be about the same. The pretreatment phase can include one application of light or there can be plural pretreatment phases. After the pretreatment phase, the controls 38 can employ the parameters 36 to deactivate the light sources (or at least substantially reduce power) for a predetermined time. The time can be selected to allow the activatable photosensitizer to diffuse into the treatment area. During the treatment phase, the controls 38 can also control energization of the light sources 14 based on control treatment parameters 36 to activate the photosensitizer, which has penetrated into the treatment area, to achieve the desired therapeutic effect through the delivery of the treatment light.

The fluence and fluence rate during the pretreatment phase can be the same or different from during the treatment phase. Additionally, in one example, the photosensitizer or other molecule that is applied during the pretreatment phase can be different from that utilized during the treatment phase. Thus, a user can program the parameters 36 according to the requisite requirements of each photosensitizer molecule, which can include both changes to fluence, fluence rate, duration, wavelength of treatment light and the like. The parameters 36 used for both pretreatment and treatment phases can be programmed by a user (e.g., via the user interface 34), default parameters can be used or some parameters can be set automatically and modified by a user.

The pretreatment phase can also employ alternative means for enhancing penetration or increasing the rate of penetration of the photosensitizer during the treatment phase. Such alternative means can be applied in the absence of or in conjunction with delivery of the treatment light, for example. As an example, the controls 38 can control the circuitry 16 at the PDT device 12, which can be configured to deliver electric current (e.g., iontophoresis), ultrasound (e.g., sonophoresis), radio frequency energy, micro needles, application of a formulary or any combination thereof into the treatment area of the patient's body 20. The controls 38 of the control system can be programmed to control or coordinate the application of such alternative pretreatment methods to render the treatment even more susceptible to a subsequent photosensitzer in the treatment phase. Additionally, one or more such alternative therapies can be applied during the treatment phase in conjunction with the treatment light.

Additionally or alternatively, the controls 38 can selectively control which of the pluralities of light sources 14 are activated from each of the PDT devices 12 depending upon the desired result and treatment light that is to be provided. A further example when the light sources 14 include independently controllable groups of light sources (e.g., implemented on respective light tiles), the controls 38 can selectively activate and deactivate different groups of light sources 14 in a given PDT device. This selective activation and deactivation can be implemented, for example, where power requirements of the system would exceed the available power from a corresponding power source 44, or if it is determined that the amount of power being delivered by activation could result in excessive heating or patient discomfort.

For example, the control system 24 may receive an indication of sensed temperature for the patient's skin from the circuitry (e.g., infrared or other thermal sensor) 16 and control the light sources 14 based on the sensed temperature. The controls 38 can be programmed with a temperature threshold (e.g., user programmable via the user interface 34) to permit the treatment area to heat up to a predetermined threshold (e.g., about 43 degrees Celsius or less). If the sensed temperature exceeds the threshold, the control system 24 can reduce the power. The control system 24 can reduce the overall power or it can reduce power selectively to one or more groups of light sources. For instance, the control system 24 can be reduced or groups of the light sources can be selectively deactivate and reactivate different groups of light sources (e.g., in a rotating pattern or randomly) to regulate the heating and delivering of power. The controls 38 thus can adjust the parameters 36 in a real time closed loop manner based on feedback, such as disclosed herein.

The control system 24 can also include a power system 46 that is utilized to deliver power to each PDT device via the power bus of the connection 26. The power system 46 can employ the power bus interface 27 to deliver the power to corresponding connector ports 28 to which the connections 26 are connected. The controls 38 can provide control signals to the power system 46 to control the power that is provided to the light sources. As disclosed herein, the amount of power during treatment can be fixed or variable during treatment. For example, the light sources 14 on the light delivery surface can be configured to deliver treatment light to the treatment area of the patient's body 20 ranging from about 20 J/cm² to about 200 J/cm² (e.g., about 80-120 J/cm² for some applications) depending on power provided via the power bus. As a further example, the fluence rate can be controlled to be within a range, such as ranging from about 10 mW/cm² to about 200 mW/cm² (e.g., ranging from about 80 mW/cm² to about 120 mW/cm²).

As a further example, the power system 46 can also include power circuitry 50 for controlling the power delivered via the power bus. The power circuitry 50 can include an arrangement of power converters (e.g., a constant current power supplies) configured to supply electrical energy to the circuitry 16 of each PDT device based on power control instructions. As an example, the power circuitry 50 can be utilized to supply power to all of the light sources concurrently with the power being distributed via the circuitry 16. As another example, the circuitry 16 can include circuitry to control routing power to corresponding groups of light sources in each PDT device 12 based on control instructions from the control system 24.

The power circuitry 50 and the circuitry 16 can be configured (e.g., as part of a distributed power system) to coordinate the distribution of electrical power to each of the light sources or groups of light sources based on the power and control information provided by the control system 24. It will be appreciated that the distribution of intelligence implemented in the circuitry 16 and 50 can vary in different example embodiments based on the teachings herein. As one example, the intelligence can be implemented in the control system 24 and power circuitry 50 for controlling the light sources 14 or groups of light sources thereof. Alternatively, the circuitry 16 can be sufficiently intelligent and robust to selectively control and deliver power to the light sources 14 or groups of light sources based upon control information received via the control bus.

Information about the treatment process (e.g., parameters and controls) as well as patient condition can be stored as treatment data 54 in the memory 30. The treatment data 54, for example, can be utilized to record parameters for a given patient such that the stored parameters can be accessed and utilized in subsequent treatments for the given patient. As a further example, if a patient can handle an increased fluence rate relative to a predetermined default, such as based upon user feedback provided via the user input device 40, such information can be stored as part of the treatment data 54. Thus, during a subsequent treatment for the given patient, the corresponding treatment data 54 for this patient can be retrieved from the memory 30 and utilized to set the initial parameters 36 to provide a customized level of treatment. Other parameters can also be set similarly to reduce the set up time for a given patient.

As a further example, the control system 24 can include a network interface 48 that enables communication of data and instructions via a network 50. The network 50 can be a local area network, a wide area network, or a combination of different various network topologies, which may include physical transmission media (e.g., electrically conductive, optical fiber media or the like) and/or wireless communications media, that can be utilized for communicating information. The network 50 or at least a portion thereof can operate in a secure manner (e.g., behind a firewall separated from public networks) and/or utilize encryption for data communications.

One or more authorized users can employ a corresponding remote device 52 to communicate with the control system 24 (or a number of such systems that may be distributed across the network). For example, the system 10 can be implemented at a patient's home or other location remote from a doctor's office or hospital facility. The remote device 52 can, for example, retrieve treatment data, such as to allow a physician or other care giver to monitor and review one or more treatment procedure. Such monitoring can include historical and/or real-time monitoring of treatment procedures. Additionally or alternatively, the remote device can be employed to adjust or authorize adjustments to one or more treatment parameters 36, such as those disclosed herein (e.g., selecting a protocol and related treatment parameters). For example, the remote device 52 can employ a user interface (not shown) to view and/or control the functions and methods implemented by the control system 24. The remote device 52 can be a computer, a work station, as well as a mobile device (e.g., a smart phone, laptop or tablet computer) that can run a corresponding application for accessing the control system 24.

A photosensitizer can be employed during the pretreatment phase, the treatment phase or both. The photosensitizer can be applied directly to the treatment area. Alternatively, the photosensitizer can be resident on the spacer 18 and transfer to the treatment area in response to placing the spacer 18 against and in contact with the treatment area. In some examples, the photosensitizer may be transferred to the treatment area in response to a stimulus.

As mentioned above, the photosensitizer can be a phthalocyanine photosensitizer. Other examples of photosensitizers include porphyrins, porphyrin precursors, porphycenes, naphthalocyanines, phenoselenazinium, hypocrellins, perylenequinones, texaphyrins, benzoporphyrin derivatives, azaporphyrins, purpurins, Rose Bengal, xanthenes, porphycyanines, isomeric porphyrins, pentaphyrins, sapphyrins, chlorins, benzochlorins, hypericins, anthraquinones, rhodanols, barbituric acid derivatives, expanded porphyrins, dipyrromethenes, coumarins, azo dyes, acridines, rhodamine, azine derivatives, tetrazolium derivatives, safranines, indocyanines, indigo derivatives, indigo triazine derivatives, pyropheophorbides, pyrrole derived macrocyclic compounds, naturally occurring or synthetic porphyrins, naturally occurring or synthetic chlorins, naturally occurring or synthetic bacteriochlorins, naturally occurring or synthetic isobacteriochlorins, naphthalocyanines, phenoxazine derivatives, phenothiazine derivatives, chalcoorganapyryllium derivatives, triarylmethane derivatives, rhodamine derivatives, fluorescein derivatives, verdin derivatives, toluidine blue derivatives, methylene blue derivatives, methylene violet derivatives, nile blue derivatives, nile red derivatives, phenazine derivatives, pinacyanol derivatives, plasmocorinth derivatives and indigo derivatives, and combinations thereof.

FIG. 2 depicts an example of a PDT device 100 in the form of a flexible panel that includes a plurality of light sources 104. In the example of FIG. 2, the panel 102 includes a plurality of light tiles 106. The tiles can be distributed across the panel 102, such as in a two-dimensional matrix of tiles. Each of the respective tiles 106 further includes a plurality of the light sources 104 distributed across the respective tile thereof such as to define a light delivery surface of the device 100. In the example of FIG. 2, the matrix of tiles includes tiles 106 distributed evenly across row and columns and in which each of the tiles has the same dimensions and configuration as other tiles.

By way of example, the length of the side edges for the tiles in the example of FIG. 2 (as well as other examples herein) can range from about 1 cm to about 4 cm. Tiles of different sizes, of course, can be provided for treating different anatomical regions that may require different amounts of conformability.

Each of the respective tiles 106 can be connected to provide a desired conformability of the panel 102 to facilitate attachment to a treatment area of the patient's skin. In one example, each pair of adjacent tiles 106 can be flexibly connected to each other to permit easy bending or flexion at a respective juncture between respective pairs of the adjacent tiles. Such connections can be implemented between adjacent edges of each of the respective adjacent pairs of tiles. As demonstrated in the example of FIG. 2, the tiles 106 can be connected to a flexible sheet of material 110, such as a woven or non woven flexible fabric. For example, each of the tiles 106 can be connected to the sheet of material 110 by an adhesive, a connector, clamp, fastener or a combination of means for connecting the tiles to the material 110. As an example, the sheet of material 110 can be textile material, such as a synthetic fiber (e.g., a polyurethane-polyurea copolymer) that is mixed with cotton or polyester.

The tiles 106 can be implemented as generally rigid plates, which are significantly more rigid than the flexible sheet of material 110. For example, the tiles 106 can be formed of a material having low electrical conductivity (e.g., an electrical insulator) as well as having a low thermal conductivity (e.g., a thermal insulator). For example, the tiles 106 can be formed of such as a printed circuit board (PCB) material (e.g., a PCB material that includes multiple insulating layers laminated together with epoxy resin composite fibers) or a ceramic material. The printed circuit board can include electrical traces to which the light sources (e.g., LEDs) and other circuitry are connected. The tiles 106 can include multiple parts assembled together to provide its structural rigidity according to the aggregate components in each tile assembly. For example, the tiles 106 can also include one or more heat sinks (e.g., see FIG. 10) of thermally conductive material attached to an opposite side from which the light sources reside. The heat sinks can be thermally connected to dissipate heat from the light sources 104 and other circuitry.

By way of further example, each of the respective tiles can be dimensioned according to the intended application of the PDT device 100. That is, the dimensions and shape of the tiles 106 can vary to provide PDT devices specially designed for placement on different anatomical areas of the patient's body.

The distribution of light sources 104 across the light delivery surface of the panel 102 can be substantially uniform. For example, a gap between the edges of adjacent tiles can be set to a distance that allows LEDs along each set of adjacent edges to be spaced apart from each other by approximately the same amount as the distance between adjacent LEDs within each respective tile.

Additionally, the connection between the adjacent edges (e.g., as provided by the flexible sheet of material 110) allows flexion at the juncture between each pair of adjacent edges of the tiles 106. The direction of this flexion can be designed to determine the types of anatomical structures to which a given PDT device can appropriately conform. Thus, in the example of FIG. 2, the PDT device 100 can fold its lateral edges 112 and 114 together and/or its anterior and posterior edges 116 and 118. As an example, the PDT device 100 can be placed on a flat surface such as a patient's back or stomach. As another example, the device 100 can be applied to a patient's arm or leg and conform to the limb by folding a pair of opposing edges 112 and 114 or 116 and 118 toward each other around the limb.

FIG. 3 depicts an example of another PDT device 150 that includes a flexible panel 152 with a plurality of light sources 154 distributed across and defining a conformable light delivery surface. Similar to the example of FIG. 2, the PDT device 150 includes a plurality of light tiles 156 that are distributed across a surface of the panel 152 in a two-dimensional matrix of tiles. In this example, the configuration of the respective tiles 156 can be designed for application to articulating joints, such as the knee or elbow.

To enhance conformability of the light delivery surface to such an articulating joint, the tiles 156 can include an arrangement of tiles having different sizes and shapes dimensioned and configured to afford greater conformability at an area designed for use over the articulating joint, such as the area demonstrated in central region 158. Each of the tiles 156 can be attached to a flexible sheet 160 similar to as disclosed above with respect to FIG. 2. In the example of FIG. 3, rows of tiles near the lateral sides 162 and 164 (and outside the central region 158) are configured as the rectangular or square tiles of equal size and shape similar to as in the example of FIG. 2. The tiles disposed in the region 158 have different shapes and sizes of tiles. For example, each of the tiles in the region 158 is demonstrated as being triangular tiles. However it would be understood and appreciated that the tiles 156 in this region 158 could have different shapes and configurations from that shown herein.

Tiles at the corners of the central region 158, indicated at 166, correspond to a triangle that is approximately one-half the size of the rectangular tiles near the lateral side edges 162 and 164, such as by diagonally sectioning the rectangular tile. Tiles located in the region 158 between the corner tiles 166 are demonstrated as triangular tiles that are approximately one quarter the size of the large rectangular tiles. Conformability of the device 150 thus depends on the flexion between each adjacent pair of tiles 154 that is provided through the flexible sheet 160 along the junctures extending between each adjacent edge of adjacent tiles. Since the tiles in the central region have more edges extending in a greater number of directions as compared the lateral columns of rectangular tiles, the device exhibits increased conformability at the central region 158. That is, in this example, the sectioned tiles located at the central region 158 not only permit flexion between edges of adjacent tiles extending anteriorally and posteriorally and laterally, but also diagonally between the respective diagonally extending edges.

As disclosed herein, each of the respective tiles 154 can be individually controlled for delivery of treatment light including the tile sections 166 and 168 and located at the central region. Alternatively, tile sections that collectively form a generally rectangular shaped tile portion can be controlled collectively as well as other groups of two or more tiles. For instance, a group of contiguous tiles can be electrically connected together as being a group that can be independently controlled by the control system, such as disclosed herein.

FIGS. 4 and 5 depict another example of a PDT device 200 in which FIG. 4 demonstrates a top elevation of a contact-side view and FIG. 5 shows the same apparatus in a perspective view. The PDT device 200 includes a plurality of light tiles of different shapes and sizes to provide a corresponding flexible light panel having a corresponding light delivery surface. For example, the panel can include rectangular (e.g., square tiles) 204 as well as triangular tiles of different sizes, such as including a larger triangular tile 206 as well as a corresponding triangular tile 208.

As disclosed herein, each of the respective tiles 204, 206 and 208 can be connected to a sheet of flexible material 210 that affords flexion at the juncture between each pair of adjacent side edges of the respective tiles. Each of the tiles 204, 206 and 208 can include an arrangement of light sources (e.g., LEDs) 212 arranged and distributed to provide treatment light to an area of skin that is positioned a predetermined distance from the light delivery surface of the device 200.

The direction of flexion and corresponding conformability of the PDT device 200 depends on the relative direction in which the side edges of each tile extend on the panel 202. For example, the large tiles 204 generally permit flexion between adjacent pair of tiles that extend in a lateral as well as an anterior-posterior direction. Each of the triangular tiles 206 and 208 also permits flexion between each of its edges and adjacent edges of another tile (if any) depending upon the direction in which the respective edges extend. For example, the large triangular tiles include side edges that extend laterally and an anterior-posterior direction as well as a corresponding diagonal edge (e.g., at about forty-five degrees from horizontal as viewed on the page).

As an example, the arrangement of tiles demonstrated in FIG. 4 can facilitate attachment of the PDT device 200 over a patient's shoulder. This arrangement of tiles, similar to other examples disclosed herein, can be considered a two-dimensional matrix of tiles having a plurality of rows and columns. It will be appreciated that pre-curved PDT device structures can also be provided, such as to facilitate application to a patient's face or other complex geometry.

FIG. 6 demonstrates an example of another PDT device 250 that includes a flexible panel 252 that includes a plurality of light sources 254 distributed across a light delivery surface of the panel 252. In the example of FIG. 6, the apparatus 250 includes a plurality of tiles 256 distributed across a panel 252. Each tile includes a plurality of light sources 254 arranged across with each respective tile to collectively provide a light delivery surface of the panel 252.

In the example of FIG. 6, each of the tiles 256 is demonstrated as an elongated rectangular tile extending across substantially the entire lateral dimension of the panel between edges 264 and 266. As an example, the length of the short side edges for the tiles in FIG. 6 may range from about 1 cm to about 4 cm while the longer side edge may range from about 6 cm to about 30 cm depending on its expected use. Thus, the elongated side edges which are adjacent to the elongated side edges of other tiles provides a flexible juncture to facilitate folding and bending of the apparatus 250 by urging the anterior-posterior edges 260 and 262 toward each other. The amount of flexion between lateral edges 264 and 266 will depend upon the flexibility of the tile itself. Tiles can be implemented as a flexible material to permit a certain amount of flexion or such tiles can be implemented from a rigid material, such that flexion between the lateral edges of the panel 252 intentionally can be limited. As disclosed herein, however, since the amount of power used to deliver the treatment light is considerable, the rigidity facilitates attaching circuitry and heat sinks to the substrate provided by the tiles, such that heat dissipation can be facilitated. The example apparatus in 250 thus can be utilized on flat surfaces as well as curved surfaces that are substantially uniform in an elongated direction (e.g., limbs).

FIG. 7 illustrates a portion of a panel 270 of a PDT device. In the example of FIG. 7, the panel 270 includes a plurality of light tiles 272 such as disclosed herein. By way of example, the tiles 272 in the example of FIG. 7 are demonstrated as being generally rectangular (e.g., square) tiles, although the tiles could have any configuration, such as disclosed herein. Each of the tiles 272 also includes a plurality of light sources 274 distributed across an exposed surface thereof for providing treatment light when activated. Each of the tiles 272 can also be attached together to provide flexion between adjacent side edges 276 to permit flexion at the juncture between the respective side edges 276. The flexion can include flexion about the juncture, which can permit rotation about an axis extending through the juncture between the side edges as well as rotational or torsional rotation at the juncture. As one example, each of the tiles is connected to a sheet of a flexible substrate 278, such as disclosed herein. The flexible substrate 278, for example, may be a woven or non woven fabric that exhibits elastic properties in one or more direction.

The example of FIG. 7 also demonstrates an electrical connection 280 between the respective tiles 272. The electrical connection 280 can provide connection for both a power bus and a control bus, such as disclosed herein. The connection 280 thus can be used to provide corresponding signals to one or more of the light sources 274 or other circuitry in the panel 270. The connection 280 can be in the form of a flexible circuit (e.g., similar to a ribbon cable). Another flexible connection 282 can extend from one of the tiles 272, such as for attachment to another tile (not shown) or may extend from the panel 270 to a corresponding connector of the apparatus (e.g., the connector port 22 of FIG. 1) that can be coupled to a control system as disclosed herein. One or both of the electrical connections 280 and 282 can be attached to the substrate 278 or such connections may remain free from connection; instead relying on the connection between the substrate 278 and each of the respective tiles to maintain the relative position of the connections 280 and 282.

Each connection 280 and 282 can include one or more electrical conductors 284. The electrical conductors 284 can carry power and/or control information and can be encapsulated by an appropriate insulating layer 286. The number of conductors 284 in each connection 280 and 282 can depend upon the type of information and the manner used to deliver power. For example, circuitry can be provided to supply power to the light sources 274 in response to control instructions from an associated control system (e.g., control system 24 of FIG. 1). By way of further example, a separate conductor in each of the connections 280 and 282 can provide for an electrical connection to each of the light sources 274 such that each light source can be selectively activated and deactivated by providing power to the respective conductors associated therewith. Alternatively, power can be distributed amongst the light sources 274 by supplying a voltage to a common power bus (or other connection) that supplies power to plural light sources. Such power bus can be located on the underside (not shown) of the respective tiles 272.

As a further example, FIG. 8 demonstrates a portion of the panel 290 similar to the example of FIG. 7, but in which the electrical connections (e.g., electrical traces) 292 and 294 are disposed directly on the flexible substrate 296. The electrical connections 292 and 294 can include electrical traces that can be applied to the surface of the substrate 296 via a heat transfer process such that the traces remain affixed directly to the substrate. The traces further can include electrical contact pads on the substrate 296, which can be contacted by corresponding pins and other types of electrical connectors implemented on the underside of the respective tiles. In this way, by contacting the pads with the pins and connectors for each respective tile, manufacture of the respective PDT device 290 may be facilitated.

FIG. 9 demonstrates an exploded view of part of a PDT device 300 demonstrating an example approach that can be utilized to fabricate the device. In the example of FIG. 9, the PDT device 300 includes a plurality of tiles 302 (two of which are demonstrated in this example). Each tile 302 includes a plurality of light sources (e.g., LEDS) 310 distributed across a surface thereof which collectively run together in the PDT device and forms a light delivery surface of the apparatus. Each of the tiles 302 can be attached to a sheet of a flexible substrate material 304, such as disclosed herein.

In the example of FIG. 9, each respective tile 302 includes a first tile portion 306 and a second tile portion 308. The first tile portion 306 can be formed of a dielectric material, such as corresponding to a printed circuit board that contains light sources 310 and related circuitry. The second portion 308 can include a heat sink as well as other circuitry that may be implemented within a respective tile 302. The second tile portion 308 can include one or more connectors 312 to enable connection with the first tile portion 306. For example, the connectors 312 can be dimensioned and configured for mating attachment with corresponding receptacles in the underside of the first tile portion 306. The attachment can provide a thermally conductive link between the heat sink of the second portion 308 and circuitry of the first tile portion 306. It will be understood and appreciated that the connectors and receptacles can be formed interchangeably between the respective tile portions 306 and 308 without distinction in this example. Additionally, one or more other structures or thermally conductive layers can be interposed between the second tile portion 308 and the first tile portion 306.

One or more corresponding apertures 314 can be formed through the flexible substrate 304 at positions corresponding to the connectors 312 such that the connectors can extend through the substrate and connect with the corresponding features of the other tile portion 306. In addition to making physical connection between the second tile portion 308 and first tile portion 306, the corresponding attachment between tile portions 306 and 308 may also result in electrical connections either through the connectors 312 or by physically contacting a portion of a corresponding trace or other connector. By aligning and attaching together the first and second tile portions 306 and 308, such as with the connectors extending through the corresponding apertures 314, the respective tile 302 can be secured relative to the flexible substrate through the connection of the tile portions. While the connections 312 are demonstrated as outwardly extending tabs, it will be understood that other means for connecting the tile portions 306 and 308 can be utilized, including screws, adhesives, friction fittings and the like.

FIG. 10 demonstrates another view of a portion of a PDT device 350 corresponding to a side view of the panel that is opposite the light delivery surface. In this example, the device 350 includes a plurality of tiles 352. The light delivery surface (not shown) would be on underside of the device 350 shown in FIG. 10, for example. The portion of the tile demonstrated in FIG. 10 (e.g., corresponding to the tile portion 308 of FIG. 9) can include a heat sink 354 configured to dissipate heat by providing an increased surface area in contact with a cooling fluid surrounding it, such as the air.

The heat sink 354 can include an arrangement of fins 356 to provide an increased surface area. In the example of FIG. 10, the fins 356 extend outwardly from a base portion 358 to terminate in an outer surface. The outer surface of the heat sink 354 can be curved in multiple directions (e.g., having a semispherical contour) so as not to provide any sharp or jagged edges that might otherwise contact a patient's body or clothing. The heat sink 354 can be provided for each of the respective tiles or, alternatively, more than one heat sink may be applied to a given tile. As yet another example, fewer than all tiles may be implemented with heat sinks.

Also demonstrated in FIG. 10, an indicator can be operatively associated with the second portion of each tile 352. The indicator 360 can be configured to indicate an operating condition associated with the tile 352. As disclosed herein, for example, light sources for a given tile 352 may be selectively activated and deactivated by a corresponding control system. The activation or deactivation of a group of tiles can be implemented via the control system or locally at the PDT device 350. The indicator 360 can indicate whether the plurality of light sources for a given tile are activated or deactivated. As an example, different color light can be utilized by the indicator 360 to identify whether or not a given tile and its corresponding light sources are activated. For example, the indicator 360 can itself be implemented as a light source (e.g., an LED) or other mechanism that may be utilized to distinguish between activated and non activated states.

Additionally or alternatively, the tiles 352 can include a switch 362 configured to selectively activate or deactivate the light sources that are distributed across the respective tile (e.g., the first tile portion 306 of FIG. 9). That is, each switch 362 can change the state of an electrical connection that in turn results in control of the light sources associated with the respective tile 352. As one example, the switch 362 can be coupled to corresponding circuitry that is implemented at each respective tile 352 that can electrically disconnect or connect the corresponding power from the tile for controlling energization of its group of light sources. Alternatively or additionally, operation of the switch 362 can provide a signal (via the corresponding control bus) to the control system that can be identified as originating from the respective tile or other group of light sources. The switch signal can in turn be utilized by the control system to selectively activate or deactivate the group of light sources depending upon the state of the switch signal.

In one example, the indicator 360 itself may be configure to operate both as an indicator and as the switch 362. The position of the switch 362 can operate as the indicator for the respective tiles. Alternatively or additionally, the indicator can include a light to indicate the condition of the tile.

FIG. 11 demonstrates an example of a PDT device 400 and an associated spacer 402. In the example of FIG. 11, the PDT device 400 provides a light panel that includes a plurality of light sources 404 to define a corresponding light delivery surface of the device 400. The light sources 404 are distributed across an arrangement of tiles that are attached to a flexible substrate 408, such as disclosed in the example in FIG. 2. Additional information about the PDT device 400 thus may be obtained with reference back to the description of FIG. 2 herein.

In the example of FIG. 11, the PDT device 400 also includes a plurality of support features 410 that extend outwardly from the light delivery surface beyond the light sources, such as by a predetermined distance. The distance that the support features 410 that extend from the substrate, for example, can approximate the predetermined distance at which the light delivery surface is to be positioned away from a treatment area. The respective support features 410 can be implemented near the junctures or edges of a selected portion of the tiles and may be affixed thereto to maintain the position and orientation of the respective features 410. For example, the protruding elements can have a base portion that is affixed to the light delivery surface (e.g., to a corresponding tile) and extend outwardly from the light delivery surface to terminate in a contact end that is spaced apart from the light delivery surface about the predetermined distance. The support features 410 can be integrally formed with a distributed subset of the tiles 406 such as to provide a monolithic structure with such tiles, or the support features can be attached to the tiles by other means of attachment (e.g., by an adhesive, ultrasonic welding or the like).

The cross section of the base of the support features 410 may be wider than the cross section of the terminal end to facilitate attachment to a corresponding spacer 402. The spacer 402 can be formed of a sheet of flexible material such as a thin film or other conformable sheet of material as disclosed herein. The spacer 402 can be easily connected and removed from the PDT device and be disposable. The spacer 402 includes a substantially planar base portion 414 and corresponding protruding elements 416. The planar portion 414 of the spacer 402 can be implemented with a thickness that is less than about or equal to one millimeter to facilitate its flexibility and conformability. In this example, the spacer protruding elements 416 can be implemented as receptacles dimensioned and configured for receiving a corresponding support feature 410 from the surface of the PDT device 400. For instance, each of the support features 410 can be located for alignment with a corresponding receptacle 416 into which it can insert partially or wholly. If the support features 410 had a length that exceeds the depth of the corresponding receptacle 416, an additional interstitial space will be provided between the light delivery surface and the substantial planar base portion 414 of the spacer 402. This additional space can allow additional airflow between the spacer 402 and the light delivery surface to facilitate cooling. The planar portion 414 of the spacer 402 can be implemented with a thickness that is less than about or equal to one millimeter to facilitate its flexibility and conformability.

FIG. 12 demonstrates another example of a PDT device 450 and an associated spacer 452. In the example of FIG. 12, the PDT device 450 is substantially identical to that shown and described in FIG. 2. Accordingly additional information about the details of the PDT device 450 can be obtained with reference back to FIG. 2 and the associated description thereof. It differs from the example in FIG. 11 in that the structural support, which in the example of FIG. 11 was provided by the support features 410 extending from the light delivery surface of the PDT device, are instead implemented within the spacer 452. Thus, in the example of FIG. 12, the spacer 452 includes protruding elements 454 that extend outwardly from a substantially planar base portion 456 of the spacer 452. The protruding elements 454 in the example of FIG. 12 can be implemented with sufficient structural rigidity to space apart the treatment area over which the apparatus and spacer are applied from the light delivery surface of the device 450. This can be implemented by having the protruding elements 454 with a thicker material than that utilized to form the base portion 456. Alternatively or additionally, a different type of material with further instructional rigidity can be implemented to provide the protruding elements 454. Both the base portion 456 and the protruding elements 454 of the spacer 452 can be formed of a substantially optically transparent material, such as disclosed herein.

FIG. 13 demonstrates an example of a PDT device and associated spacer such as demonstrated in the examples of FIGS. 11 and 12. For purposes of the following description, it is presumed that the device and spacer correspond to those disclosed in relation to FIG. 12, and corresponding like reference numerals will be utilized to refer to parts previously introduced. As demonstrated in the example of FIG. 13, the device 450 includes opposing ends 460 and 462 that are urged towards one another about a longitudinal access 464 that extends through the apparatus, simulating a type of configuration that can be utilized to attach the device and spacer about a patient's limb. An example of the PDT device conforming to a patient's limb 470 is demonstrated in the example of FIG. 14.

Similar to the example of FIG. 10, an exterior surface of the PDT device 450 includes a plurality of heat sinks 472. FIG. 13 thus further demonstrates an example embodiment in which respective tiles can include first and second tile portions one of which can include the heat sinks and the other which includes the plurality of light sources utilized for providing the treatment light to the patient's skin. Additionally, similar to the example of FIG. 7, the device 450 can also include an indicator 474 and/or a switch 476 associated with each tile. It is to be appreciated that the switch 476 and/or indicator 474 can be implemented in the same general area such that the switch can be activated via a push button and in turn illuminate to indicate the status of the group of light sources associated with the respective tile, such as disclosed herein.

In other embodiments, the switch and light source could be implemented at different locations on the second portion of the respective tile or a given tile can include one but not the other. Additionally while a switch is demonstrated on each of the tiles in the example of FIG. 13, it is to be understood and appreciated that a given switch can be employed to selectively activate or deactivate groups of light sources that may correspond to more than a single tile such as via a corresponding electrical connection between a switch and each tile to which it is configured to control.

FIG. 15 demonstrates an example of the PDT device 450 of FIG. 13, without the spacer, connected to a control system 480, although it is understood that any of the example PDT devices can be utilized and each includes a corresponding spacer sheet. Similar reference numbers in FIG. 15 denote similar features previously introduced with respect to FIG. 13. For example, the PDT device 450 is coupled to the control system 480 via a connection 482. As described with respect to FIG. 1, the connection 482 can include a power bus, a control bus or a combination of power and control buses within a common cable. Alternatively, multiple cables could be utilized in other embodiments. The connection 482 can be connected to a corresponding connector port 484 of the control system 480, such as via a set of pins or other suitable connectors for enabling communication of power and/or control signals between the control system 480 and circuitry on the device 450. As disclosed herein, circuitry on the device can include the LEDs, control circuits, switches and other circuitry depending upon how electronics are distributed between the device 450 and the control system 480.

The control system 480 can also include a display 486, which may display text and/or graphics associated with the operation of the PDT device 450 as well as one or more other apparatuses that could be attached to other connector ports 484. Additionally or alternatively, the display 486 can correspond to a touch screen that can be utilized to access a user interface (e.g., the user interface 34 of FIG. 1) to receive user inputs. Such user inputs can correspond to setting control parameters associated with operation (e.g., delivery of treatment light, such as power duration, wavelength or the like) of the system 480. Other inputs may be provided to the control system 480 via the switch 476 that is provided on panels of the device 450. Additionally or alternatively, a keypad or buttons or other user input devices, demonstrated schematically at 488, may be implemented on or be remotely connectable to the control system 480. Connection of such other input devices may be via a physical connection or may be via a wireless link (e.g., WiFi, Bluetooth, infrared or other types of wireless communication).

In the example of FIG. 15, the control system 480 is demonstrated as being implemented in a portable housing 490 that includes a handle 492 for ease of transport of the device. It will be understood and appreciated that the control system 480 can supply power via the connection 482 to the apparatus. Accordingly, the control system 480 may be electrically connected to a power source (e.g., one or more wall outlets), which may vary depending upon the power requirements of the system 480. For instance since multiple PDT devices 450 may be connected to a common control system 480, it may be appropriate to electrically connect the control system to multiple power sources such that the total power available can be increased accordingly. Additionally or alternatively, the control system 480 may be implemented with an internal power source for supplying electrical energy to the light sources and other circuitry resident on the PDT device 450.

In view of the foregoing structural and functional features described above, example methods of treatment and related control routines will be better appreciated with reference to FIGS. 16 and 17. While, for purposes of simplicity of explanation, the example methods are shown and described as executing serially, it is to be understood and appreciated that the present examples are not limited by the illustrated order, as some actions could in other examples occur in different orders and/or concurrently from that shown and described herein.

FIG. 16 demonstrates an example of a method that can be utilized for providing photodynamic therapy to one or more treatment areas of a patient. The method 500 can be implemented using a PDT system such as shown and disclosed herein. The method 500 begins at 504 in which the PDT device can be coupled to the control system. This can be implemented via a physical connection and/or wireless connection, that is the power control system and the control system may connect differently to the PDT device. For instance, the power system can connect via electrical conductive link and control system may be coupled to the device via physical or wireless link. In some cases, the connection at 504 may be permanent.

At 506, a photosensitizer can be applied to the treatment area. For example, the photosensitizer can be implemented as a phthalocyanine photosensitizer, such as a class of phthalocyanine photosensitizers that includes a diamagnetic metal or metalloid (e.g., Pc 4). The photosensitizer can be applied and spread manually (e.g., via a person's fingers) or an applicator can be employed to apply the photosensitizer to the treatment area. In other examples, a layer of the photosensitizer can be coated on a contact surface of the spacer and be applied to the treatment area following contact between the spacer and the treatment area.

At 508, each PDT device can be attached to the treatment area. As disclosed herein, the attachment at 508 includes use of one or more spacers between a light delivery surface of the PDT device and the treatment area. The spacer can be an optically transparent material such as disclosed herein (e.g., with respect to the examples of FIGS. 11, 12 and 13). As an example, the PDT device can be attached via one or more straps that can be utilized to urge the panel and corresponding spacer into a conforming relation relative to the treatment area. Alternatively or additionally, an attachment may be facilitated by applying an optically transparent adhesive to the spacer to facilitate attachment of the spacer and panel to the treatment area. In some examples, the PDT device can simply be placed on a treatment area such as where it corresponds to a generally flat structure such as the back, abdomen or the like. As an alternative example, an optically transparent adhesive can be employed to attach a contact surface of the spacer to the panel in overlying relation to the light delivery surface, to attach the panel to the patient or a combination thereof (e.g., using a double-sided adhesive).

The steps 504, 506 and 508 can be repeated for each treatment area as part of a preparation procedure for PDT. In this way a corresponding PDT device can be selected according to the dimensions and configurations of each treatment area that is to be treated during the method 500. In some situations, the PDT panels may include a similarly dimensioned and configured light delivery surface. In other examples, differently configured and dimensioned PDT panels can be utilized for treating a patient. The particular arrangement and selection of PDT devices will vary from patient to patient depending upon the severity and size of the treatment areas.

At 510, the PDT treatment can be performed, such as disclosed herein. After the PDT treatment has been completed the treatment may end at 512. It is to be appreciated that the method 500 of treatment demonstrated in the example of FIG. 16 can be repeated over a plurality of visits depending upon the severity and size of the area being treated as well as other treatment parameters disclosed herein. Additionally, while in some examples, multiple PDT devices and associated spacers can be used to treat several areas concurrently, in other examples, the same PDT device and spacers can be relocated to treat different areas at different time intervals.

FIG. 17 demonstrates an example of a control method 550 that can be implemented by a control system, (e.g., the control system of FIG. 1). The method 550 can be implemented as computer readable instructions, such as can be stored in a non-transitory medium (e.g., a memory device). The instructions in the medium may also be executed by a processing unit (e.g., the processor 32 of FIG. 1) to implement the corresponding functions.

The method 550 begins at 552 in which the PDT system is powered up. At 554, initial parameters can be set. The initial parameters can correspond to a set of default parameters for the system. Alternatively or additionally, the initial parameters can be customized for a given patient. In some examples the initial parameters for a given patient may be obtained from memory such as based upon those that were utilized during one or more previous treatment procedures. The parameters can include, for example, time intervals, electrical power (e.g., voltage and current), which can correspond to a fluence and fluence rate of treatment light.

At 556, a corresponding protocol can be loaded, such as may be selected in response to a user input. The protocol can be fixed for a given system. Alternatively or additionally, a protocol may be programmed at treatment time such as in response to a user input. For example, multiple protocols can be established depending upon various patient characteristics and the number of PDT devices that are to be utilized during a given course of treatment. Once the protocol has been loaded, corresponding to the current course of treatment and related parameters, the method can proceed to 558.

At 558, the method can operate to activate the light sources based upon the parameters at 554. The light sources can in turn supply a treatment light to the patient area at the patient's skin. As disclosed herein, the light sources can be operative to provide the treatment light with a selected fluence and fluence rate onto the treatment area at a predetermined distance from the light delivery surface. This predetermined distance can be maintained by the use of a spacer such as disclosed herein.

At 560, instructions or feedback can be received by the control system. A determination can be made at 562 to ascertain whether adjustment of the control process is required. If adjustment is required (YES), the method can proceed to 564 in which parameters can be adjusted accordingly. The instructions or feedback received at 560 can correspond to a user input such as can be provided by a patient, or a treating physician or technician. Feedback can also be provided automatically based on one or more sensed conditions such as can be implemented by circuitry at the PDT device. Such sensors can, for example, detect temperature of the patient's skin that is being treated, detect moisture or it can be based upon feedback corresponding to the parameters implemented by the circuitry such as including temperature of the circuitry, electrical current or voltage.

Moreover such feedback or instructions can correspond to signals indicating to selectively activate or deactivate one or more groups of light sources, such as in response to a user input. Such user input can be provided at the PDT device remote from the control system and sent via control bus. Alternatively or additionally, groups of light sources can be selectively activated and deactivated in response to controls provided at the control system (e.g., via a user input device such as a control screen, keypad or the light). From 564 the method returns to 558 to activate the light sources based upon the current state of control parameters. Thus, during treatment the method 550 may loop between 558 and 564.

If no adjustment is required at 562 (NO), indicating a steady state operating condition, the method can proceed from 562 to 566. At 566 a determination can be made as to whether treatment has ended. For example, the treatment duration can be established by a timer, such as can be set based upon the protocol loaded at 556. Thus, if the treatment has not ended and no parameters are adjusted (NO), the method can proceed from 566 back to 558 and continue. In response to determining that the treatment has ended at 566 (YES), the method can proceed from 556 to 568 in which the light sources are deactivated accordingly. From 568 the method can proceed to 570 in which the system can be powered down. The control system may remain active to await additional instructions. For example, power down may be implemented in response to a user turning off a corresponding power switch.

As disclosed herein, a treatment protocol that is loaded at 556 can correspond to a multi-hit or multi-phase treatment. In this example, such protocol can be implemented by making appropriate adjustments to the parameters at 564. As an example, for an initial phase, which can correspond to a pre-treatment phase, the method can proceed from 556 to 558 and activate the light sources in accordance with the parameters for the pre-treatment phase. The pre-treatment phase, for example, may be implemented to facilitate the penetration of an activatable photosensitizer into the patient's treatment area. During such pre-treatment phase, feedback can be implemented similar to that described above.

At 562, a determination is made as to whether adjustments are required based on the feedback. In this multi-phase treatment example, such adjustment may be required during pretreatment and/or when the first phase has ended. For example, if a given phase has ended, the method can proceed to 564 and adjust parameters to deactivate the light sources at 558 to allow time sufficient to allow diffusion of the photosensitizer further into the treatment area. As an example, such deactivation time may be five minutes or less, although different times may be utilized depending upon the parameters employed during the pre-treatment phase as well as the condition of the treatment area. Thus, a timer (e.g., a delay) may be set to provide for the diffusion of the photosensitizer. Once the diffusion time period has expired, it can be determined at 562 that further adjustment is required, and operating parameters can be adjusted to reactivate the light sources, which can be for a next pretreatment phase or the corresponding treatment phase. If necessary, additional photosensitizer can be applied between the pretreatment and treatment phase. During the treatment phase, the parameters (e.g., duration and electrical power) can be set to activate the light sources to achieve the desired therapeutic effect of exciting the photosensitizer. Feedback can be employed during the treatment phase as well at 560 to adjust parameters as may be appropriate. Once it has been determined that multi-phase treatment has ended, indicating that no additional treatment phases are required for this process, the method can proceed to 568 and deactivate the light sources and the treatment can ended, such as may include powering down the system at 570.

What have been described above are examples. It is, of course, not possible to describe every conceivable combination of components or methods, but one of ordinary skill in the art will recognize that many further combinations and permutations are possible. Accordingly, the invention is intended to embrace all such alterations, modifications, and variations that fall within the scope of this application, including the appended claims. Additionally, where the disclosure or claims recite “a,” “an,” “a first,” or “another” element, or the equivalent thereof, it should be interpreted to include one or more than one such element, neither requiring nor excluding two or more such elements. As used herein, the term “includes” means includes but not limited to, and the term “including” means including but not limited to. The term “based on” means based at least in part on. 

1. A photodynamic therapy system, comprising: a flexible panel comprising a plurality of light sources distributed across a conformable light delivery surface thereof, the plurality of light sources being configured to provide a treatment light to achieve a desired therapeutic effect at a predetermined distance from the light delivery surface; and a spacer configured at the light delivery surface, in an overlying relationship with at least some of the plurality of light sources, to position the light delivery surface at the predetermined distance from a treatment area of a patient.
 2. The system of claim 1, wherein the panel comprises a plurality of tiles, each of the plurality of tiles comprising multiple light sources distributed across the respective tile thereof, each of the plurality of tiles being flexibly connected to at least one other adjacent tile or to a common flexible substrate to provide the conformable light delivery surface.
 3. The system of claim 1, wherein the spacer further comprises a sheet of flexible material having a substantially planar portion from which a plurality of protruding elements extend outwardly by about the predetermined distance.
 4. The system of claim 3, wherein the plurality of protruding elements are distributed generally evenly across the substantially planar portion at multiple locations to maintain the predetermined distance between the light delivery surface and the treatment area.
 5. The system of claim 3, wherein the plurality of protruding elements extend from the substantially planar portion to terminate in a contact surface thereof configured to engage the treatment area at a plurality of spaced apart locations.
 6. The system of claim 3, wherein the light delivery surface comprises a plurality of support features that extend outwardly from the light delivery surface beyond the plurality of light sources, the plurality of protruding elements including receptacles configured to receive the support features therein. 7-8. (canceled)
 9. The system of claim 1, wherein the spacer comprises a flexible sheet of material that is optically-transparent for at least a desired wavelength of light from the plurality of light sources and that is resistant to transfer of fluids between the treatment area of the patient's skin and the light delivery surface.
 10. (canceled)
 11. The system of claim 1, further comprising a controller configured to energize the plurality of light sources to control the treatment light delivered to the treatment area of patient's skin wherein the controller is programmed to selectively adjust the delivery of treatment light based on feedback. 12-13. (canceled)
 14. The system of claim 11, wherein the panel comprises a plurality of tiles, each of the plurality of tiles comprising multiple light sources distributed across the respective tile thereof, each of the plurality of tiles being connected to provide the conformable light delivery surface, wherein the controller is programmed to selectively activate and deactivate each of the plurality of tiles such that the only the activated tiles are operative to deliver the treatment light.
 15. The system of claim 14, wherein the controller is configured to selectively activate or deactivate an indicator associated with each light tile to identify whether the respective light tile is activated or deactivated.
 16. The system of claim 11, wherein the controller is programmed to implement multi-delivery time periods, corresponding to a pretreatment phase and a subsequent treatment phase, wherein the controller is programmed to control energization of the plurality of light sources based on operating parameters sufficient to afford enhanced penetration of an activatable photosensitizer into at least a portion of the treatment area of the patient's skin during the pretreatment phase, and wherein the controller is programmed to control energization of the plurality of light sources based on operating parameters sufficient for activating the activatable photosensitizer to achieve a therapeutic effect in response to delivery of the treatment light during the treatment phase. 17-20. (canceled)
 21. The system of claim 16, the controller being programmed to vary at least one of fluence or fluence rate during at least one of the pretreatment phase and the treatment phase.
 22. (canceled)
 23. The system of claim 2, wherein each of the plurality of tiles are arranged in a two-dimensional matrix, which defines the light delivery surface and is conformable about at least one dimension of the two-dimensional matrix to facilitate attachment to the treatment area, and wherein the two-dimensional matrix is dimensioned and configured to conform to patient anatomy that includes the treatment area of patient's skin, the spacer being sufficiently pliant to follow the configuration of the light delivery surface to which it is removably attached while also maintaining the light delivery surface at the predetermined distance from the treatment area of the patient's skin.
 24. The system of claim 23, wherein the two-dimensional matrix is dimensioned and configured to conform to patient anatomy that includes the treatment area of patient's skin, the spacer being sufficiently pliant to follow the configuration of the light delivery surface to which it is removably attached while also maintaining the light delivery surface at the predetermined distance from the treatment area of the patient's skin.
 25. The system of claim 23, wherein at least some of the plurality of tiles are configured with a different size and shape than other of the plurality of tiles to facilitate conformability to the treatment area of patient's skin, the different shapes comprising at least one of rectangular and triangular. 26-28. (canceled)
 29. The system of claim 1, wherein each of the plurality of tiles comprises an electrically and thermally insulating material, each of the plurality of tiles comprises a first portion, which includes the light delivery surface and extends from a first side surface of the sheet of flexible material, and a second portion that extends from a second side surface of the sheet of flexible material opposite the first side surface, the first portion and second portion of each of the plurality of tiles being secured together to sandwich an adjacent portion of the sheet of flexible material to help hold the light tiles in the arrangement relative to the sheet of flexible material.
 30. (canceled)
 31. The system of claim 29, wherein the second portion of at least a substantial number of the plurality of tiles further comprises a heat sink configured to dissipate heat from the respective tiles.
 32. The system of claim 29, further comprising: a switch operatively associated with at least a substantial number of the plurality of tiles and configured to selectively activate or deactivate a group of multiple light sources; and an indicator associated with the second portion of each of the plurality of tiles and configured to indicate whether the plurality of light sources for a given tile are activated or deactivated. 33-38. (canceled)
 39. The system of claim 1, wherein each of the plurality of tiles further comprises a printed circuit board, which includes circuitry to provide power to the plurality of light sources, and a control bus disposed on the sheet for carrying control signals from the connector to each of the plurality of tiles, at least some of the light tiles comprising circuitry that is independently addressable via the control bus to selectively control operation of the multiple light sources for each of the plurality of tiles. 40-47. (canceled)
 48. A photodynamic therapy device, comprising: a plurality of generally rigid tiles, each of the plurality of tiles comprising a plurality of light sources distributed across a respective surface thereof, each of the plurality of tiles being flexibly connected in a distributed arrangement to provide a conformable light delivery surface, the plurality of light sources being configured to receive electrical power and provide a treatment light to achieve a desired therapeutic effect at treatment area located a predetermined distance from the light delivery surface.
 49. The device of claim 48, wherein the distributed arrangement of the plurality of tiles comprises a two-dimensional matrix of tiles dimensioned and configured to conform to patient anatomy that includes the treatment area.
 50. The device of claim 48, wherein at least some of the plurality of tiles are configured with a different size and shape than other the plurality of tiles to facilitate conformability to the treatment area of a patient's skin.
 51. (canceled)
 52. The device of claim 48, wherein each tile is at least one of flexibly connected to at least one other adjacent tile or to a common flexible substrate to provide a flexible juncture between edges of each respective pair of adjacent tiles, whereby conformability of the light delivery surface to the treatment area is facilitated.
 53. The device of claim 52, wherein the common flexible substrate further comprising a sheet of flexible material, the plurality of tiles comprising a material that is electrically and thermally insulating and being attached to the sheet of flexible material such that the sheet of flexible material forms the flexible juncture between adjacent tiles; each of the plurality of tiles comprising a first portion extending from a first side surface of the sheet of flexible material to terminate in the light delivery surface, and a second portion that extends from a second side surface of the sheet of flexible material opposite the first side surface; and the first portion and second portion of each of the plurality of tiles being secured together to sandwich an adjacent portion of the sheet of flexible material to help hold the tiles in the arrangement relative to the sheet of flexible material. 54-55. (canceled)
 56. The device of claim 53, wherein the second portion of at least a substantial number of the plurality of tiles further comprises a heat sink configured to dissipate heat from the respective tiles.
 57. The device of claim 48, further comprising a switch operatively associated with at least a substantial number of the plurality of tiles and configured to selectively activate or deactivate a group of multiple light sources.
 58. The device of claim 48, further comprising an indicator associated with the second portion of at least a substantial number of the plurality of tiles and configured to indicate whether a respective group of light sources are activated or deactivated. 59-60. (canceled)
 61. The device of claim 48, further comprising: a control bus disposed on the sheet for carrying control signals from the connector to at least some of the plurality of tiles; and circuitry on the at least some of the plurality of tiles that is independently addressable via the control bus to selectively control operation of the plurality of light sources; and a controller configured to operate the plurality of light sources to provide the treatment light at the predetermined distance from the light delivery surface.
 62. (canceled)
 63. The device of claim 48, further comprising a spacer comprising a disposable sheet of flexible and optically transparent material that is dimensioned and configured to engage the light delivery surface, the spacer being configured at the light delivery surface of a subset of the plurality of tiles to space the light delivery surface the predetermined distance apart from and in an overlying relationship with the treatment area of a patient. 64-70. (canceled)
 71. The device of claim 48, wherein the electrically and thermally insulating material comprises printed circuit board material, which includes circuitry to provide power to the plurality of light sources.
 72. A method for photodynamic therapy (PDT), comprising: applying a photosensitizer to a treatment area of a patient's skin; attaching a PDT device to cover at least a substantial portion of the treatment area, the PDT device comprising a plurality of light sources distributed across a conformable light delivery surface such that, following the attaching, a spacer at the light delivery surface separates the conformable light delivery surface in an overlying spaced apart relationship and from the treatment area by approximately a predetermined distance; and controlling the plurality of light sources to provide a treatment light to activate the photosensitizer applied at the treatment area located the predetermined distance from the light delivery surface.
 73. The method of claim 72, wherein the spacer comprises a sheet of a flexible and substantially optically transparent material, the sheet being interposed between the light delivery surface and the treatment area to prevent contact between the light delivery surface and at least one of the photosensitizer or the treatment area, wherein the method further comprises applying the sheet to one of the light delivery surface or the treatment area such that support features at the light delivery surface are aligned with receptacles formed in the sheet. 74-77. (canceled)
 75. The method of claim 72, further comprising, selectively adjusting the delivery of treatment light based on feedback, the feedback comprising at least one of a user input corresponding to at least one of feedback from a patient or a determination of a user and a sensor signal indicative a of a sensed condition; and employing an indicator to identify whether a group of light sources is activated or deactivated. 79-81. (canceled)
 82. The method of claim 72, wherein the controlling comprises controlling activation of the plurality of light sources in a pretreatment phase and a subsequent treatment phase, wherein the pretreatment phase at least one of (i) enhances penetration of the photosensitizer into the treatment area for the subsequent treatment phase, or (ii) increases a rate of penetration for the photosensitizer into the treatment area for the subsequent treatment phase.
 83. The method of claim 82, further comprising controlling energization of the plurality of light sources based on operating parameters sufficient to afford enhanced penetration of the photosensitizer into at least a portion of the treatment area of the patient's skin during the pretreatment phase, and controlling energization of the plurality of light sources based on operating parameters sufficient for activating the activatable photosensitizer to achieve a therapeutic effect in response to delivery of the treatment light during the treatment phase. 84-99. (canceled) 